Buggy code:
public class FileUtils { private static final FileUtils PRIMARY_INSTANCE = new FileUtils ( ) ; private static Random rand = new Random ( ( ( System . currentTimeMillis ( ) ) + ( Runtime . getRuntime ( ) . freeMemory ( ) ) ) ) ; private static boolean onNetWare = Os . isFamily ( "netware" ) ; private static boolean onDos = Os . isFamily ( "dos" ) ; private static boolean onWin9x = Os . isFamily ( "win9x" ) ; private static boolean onWindows = Os . isFamily ( "windows" ) ; static final int BUF_SIZE = 8192 ; public static final long FAT_FILE_TIMESTAMP_GRANULARITY = 2000 ; public static final long UNIX_FILE_TIMESTAMP_GRANULARITY = 1000 ; public static final long NTFS_FILE_TIMESTAMP_GRANULARITY = 1 ; private Object cacheFromUriLock = new Object ( ) ; private String cacheFromUriRequest = null ; private String cacheFromUriResponse = null ; public static FileUtils newFileUtils ( ) { } public static FileUtils getFileUtils ( ) { } protected FileUtils ( ) { } public URL getFileURL ( File file ) throws MalformedURLException { } public void copyFile ( String sourceFile , String destFile ) throws IOException { } public void copyFile ( String sourceFile , String destFile , FilterSetCollection filters ) throws IOException { } public void copyFile ( String sourceFile , String destFile , FilterSetCollection filters , boolean overwrite ) throws IOException { } public void copyFile ( String sourceFile , String destFile , FilterSetCollection filters , boolean overwrite , boolean preserveLastModified ) throws IOException { } public void copyFile ( String sourceFile , String destFile , FilterSetCollection filters , boolean overwrite , boolean preserveLastModified , String encoding ) throws IOException { } public void copyFile ( String sourceFile , String destFile , FilterSetCollection filters , Vector filterChains , boolean overwrite , boolean preserveLastModified , String encoding , Project project ) throws IOException { } public void copyFile ( String sourceFile , String destFile , FilterSetCollection filters , Vector filterChains , boolean overwrite , boolean preserveLastModified , String inputEncoding , String outputEncoding , Project project ) throws IOException { } public void copyFile ( File sourceFile , File destFile ) throws IOException { } public void copyFile ( File sourceFile , File destFile , FilterSetCollection filters ) throws IOException { } public void copyFile ( File sourceFile , File destFile , FilterSetCollection filters , boolean overwrite ) throws IOException { } public void copyFile ( File sourceFile , File destFile , FilterSetCollection filters , boolean overwrite , boolean preserveLastModified ) throws IOException { } public void copyFile ( File sourceFile , File destFile , FilterSetCollection filters , boolean overwrite , boolean preserveLastModified , String encoding ) throws IOException { } public void copyFile ( File sourceFile , File destFile , FilterSetCollection filters , Vector filterChains , boolean overwrite , boolean preserveLastModified , String encoding , Project project ) throws IOException { } public void copyFile ( File sourceFile , File destFile , FilterSetCollection filters , Vector filterChains , boolean overwrite , boolean preserveLastModified , String inputEncoding , String outputEncoding , Project project ) throws IOException { } public void setFileLastModified ( File file , long time ) { } public File resolveFile ( File file , String filename ) { } public static boolean isContextRelativePath ( String filename ) { } public static boolean isAbsolutePath ( String filename ) { } public static String translatePath ( String toProcess ) { } public File normalize ( final String path ) { } public String [ ] dissect ( String path ) { char sep = File . separatorChar ; path = path . replace ( '//' , sep ) . replace ( '\\' , sep ) ; if ( ! ( FileUtils . isAbsolutePath ( path ) ) ) { throw new BuildException ( ( path + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>an<seq2seq4repair_space>absolute<seq2seq4repair_space>path" ) ) ; } String root = null ; int colon = path . indexOf ( ':' ) ; if ( ( colon > 0 ) && ( ( FileUtils . onDos ) || ( FileUtils . onNetWare ) ) ) { int next = colon + 1 ; <START_BUG> root = path . substring ( 0 , next ) . toUpperCase ( ) ; <END_BUG> char [ ] ca = path . toCharArray ( ) ; root += sep ; next = ( ( ca [ next ] ) == sep ) ? next + 1 : next ; StringBuffer sbPath = new StringBuffer ( ) ; for ( int i = next ; i < ( ca . length ) ; i ++ ) { if ( ( ( ca [ i ] ) != sep ) || ( ( ca [ ( i - 1 ) ] ) != sep ) ) { sbPath . append ( ca [ i ] ) ; } } path = sbPath . toString ( ) ; } else if ( ( ( path . length ( ) ) > 1 ) && ( ( path . charAt ( 1 ) ) == sep ) ) { int nextsep = path . indexOf ( sep , 2 ) ; nextsep = path . indexOf ( sep , ( nextsep + 1 ) ) ; root = ( nextsep > 2 ) ? path . substring ( 0 , ( nextsep + 1 ) ) : path ; path = path . substring ( root . length ( ) ) ; } else { root = File . separator ; path = path . substring ( 1 ) ; } return new String [ ] { root , path } ; } public String toVMSPath ( File f ) { } public File createTempFile ( String prefix , String suffix , File parentDir ) { } public File createTempFile ( String prefix , String suffix , File parentDir , boolean deleteOnExit ) { } public boolean contentEquals ( File f1 , File f2 ) throws IOException { }

Fix:
root = path . substring ( 0 , next ) ;